Column addition · Year 3

In Year 3 you learn: column addition of 3-digit numbers and carrying.

Column addition is a written method for adding numbers too big to add in your head. Line the numbers up by place value, add one column at a time from the ones, and carry 1 into the next column when a column makes 10 or more.

Key facts

• Line up the digits by place value: ones under ones, tens under tens (and decimal points under each other).
• Always start with the ones column, on the right.
• Adding: if a column makes 10 or more, write the ones digit and carry 1 into the next column.
• Check: answer − one of the numbers = the other number.

Worked examples

Other years

• Column addition · Year 4
• Column addition · Year 5